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MGL Avionics EFIS

Lycoming Engine Sender Installation Guide

This manual is intended to be a Quick Reference for installing certain engine senders on a Lycoming engine.

It should be seen as a supplement to the MGL Avionics EFIS Installation Manual, the RDAC

Installation Manual, and the Installation Sheets provided with the UMA Tach Sender, UMA Fuel Pressure Sender, and Floscan and EI Red Cube Flow Senders.

Where shown, Sender setups are correct for the type of sender being shown to be installed, and

all setups should be made as shown. However, temperature and pressure parameters are shown for an example Lycoming IO-360 engine, and should just be used as a guideline. Your

aircraft/engine manual is the correct reference for all parameters.

Use these sender settings – not these parameters!

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MGL Avionics EFIS

Lycoming Engine Sender Installation Guide

CONTENTS

Engine Compartment Overview Page 3 RDAC Installation Overview Page 4

RDAC Installation Notes Page 5 OAT Probe Installation Page 5

EGT Probe Installation Page 6 CHT Probe Installation Page 7

Extending CHT and EGT Probes Instructions Page 8 Oil Temp Sender Installation Page 9

Oil Pressure Sender Installation Page 10 Manifold Pressure Setup Page 11

Fuel Flow Sender Installation Page 12 Tach Sender Installation Page 13

Fuel Pressure Sender Installation Page 14

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RDAC mounted high on the firewall, away from

exhaust, on standoffs to prevent contact with

the firewall

Oil Pressure sender mounted with clamp to

the firewall

Oil Temp sender

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RDAC Installation

Heavy gauge Ground wire run directly to

Engine Block – very important

Ground bus for connecting RDAC

Ground (Black Supply Wire) as well as all

sender Ground wires directly to Engine Block

and each other.

RDAC Power and Ground wires

RDAC Data Line – run through grommet in

firewall to EFIS

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RDAC Installation Notes

• Mount RDAC on standoffs to keep off the

firewall • Mount RDAC high up to keep away from

exhaust

• Install a Ground and Power Bus and connect Ground side to Engine Block with

heavy gauge wire. Important! Without this many of the engine senders will not read

correctly. • Connect RDAC Ground (Black Ground supply line out of the top of the RDAC) directly to this bus

• Connect all Ground wires from any engine senders requiring a Ground to this bus

• Take Power for RDAC from Secured Power Output from the back of the EFIS if you want

the RDAC to be powered by the EFIS backup battery during power failure. If no backup

battery present, power RDAC from Avionics/EFIS Master. Use the Power side of this bus to power RDAC and all engine senders

that require power

OAT Probe (outside/ambient air temp probe)

• Although the OAT Probe is not part of the RDAC

installation, it is shown here since its installation

needs to be considered. • The OAT probe should be

installed preferably out of the sun (such as under a

gear fairing as shown here), and away from any

exit air from the engine cowling (or exhaust)

• The OAT probe wires should be routed as far

away as possible from any RF (Radio and

Transponder) power/ground leads or

antennas and coax

RDAC Power and Ground Wires

External Taxi Camera

installed on gear leg (if required)

OAT Probe mounted

under gear fairing out of the sun

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EGT Probe Installation

• Install the EGTs between 2 and 4 inches down the exhaust pipes (based

on engine manufacturer recommendations) • Make sure EGTs do not protrude into cowling

• Use ‘EGT, Small Clamps’ on most installations. When pipes are greater than 1 ½” diameter, then ‘EGT, Large Clamps’ are recommended

• Drill a ¼” hole for clamp-type probes • Use Thermocouple Channels TC1 through TC4 if you have a 4-cyl engine.

Use TC1 through TC6 if you have a 6-cyl engine. • Remember that all EGTs are type K thermocouples and that Yellow is Positive and Red is

Negative • Extend EGT leads if necessary with type-K extension wire (see instructions later in manual)

Wiring:

Connect to Thermocouple Channels TC1 and upwards (no gaps)

Yellow Positive

Red Negative

Clamp-type EGT probes

Parts Required: 4 x EGT, small

clamps

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CHT Probe Installation

• Screw 3/8-24 Threaded CHT probes into recesses in cylinders (no washers required)

• Use Thermocouple Channels TC5 through TC8 if you have a 4-cyl engine. Use TC7 through TC12 if you have a 6-cyl engine.

• Remember that some CHTs are type-J thermocouples (these can be used). MGL Avionics supplies only type-K thermocouples

• Remember that with type-K thermouples that Yellow is Positive and Red is Negative

Wiring:

Connect to Thermocouple Channels starting from first

availab le (not used by EGTs) and upwards (no gaps)

Yellow Positive

Red Negative

CHT probe screwed into threaded recess in

cylinder near sparkplug

Parts Required: 4 x CHTBAYO, Extension Wire

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Extending CHT and EGT Probes • MGL Avionics instruments feature cold-junction compensation, which means that the temperature

of the cold junct ion of the thermocouple is measured (at the RDAC) and this temperature is used to compensate for ambient temp with the small voltage readout between the 2 alloys in the thermocouple. For this reason it is important that type-K thermocouples are extended with type-K

extension wire directly to the RDAC • You can use the same extension wire for CHTs or EGTs • Length is not crit ical – you can use different lengths (within reason) and there will be no noticeable

difference in temp reading Our CHT extension k it includes type-K thermocouple wire, splice barrels, and a length of meltable-inner heat shrink tubing. This heat shrink gets quite soft inside when it is heated up, and this eliminates all air inside the splice and makes an airtight seal. We use Raychem SCL-3/16 heat shrink.

1. Strip the CHTs and make little loops with the ends.

Do the same with the type-K extension wire. Prepare the splice barrels and heat shrink.

2. Place a splice barrel and short length of meltable-

inner shrink wrap on the wires. Lay the CHT and type-K extension loops over each other.

3. Slide the splice barrel over the parallel loops.

4. Crimp the splice barrel with a crimping tool (use a

crimping tool with a grip for non-insulated terminals – the ones that have a cradle on one side and pierce a

small hole on the other).

5. Slide the meltable-inner heat shrink over the splice

and heat with a heat gun or lighter.

6. That is a solder-free, airtight and airless parallel

thermocouple splice. Repeat as necessary.

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Oil Temperature Probe Installation

• Screw in 5/8-18 UNF Threaded Westach Oil Temp sender as shown, with crush washer

• Use adapter fitt ing if required • Sender has 2 black wires (interchangeable) – connect one wire to Oil

Temp input and the other to RDAC Ground • Note that EFIS will read 32 deg F (0 deg C) until you reach operating

temp of 70 deg F

Wiring:

Connect 2 black wires (any way) as follows

Black Oil Temp Input

Black RDAC Ground

Oil Temp sender safety-wired in place

Crush washer under Oil Temp sender

Parts Required: 1 x Westach Oil Temp Sender

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Oil Pressure Probe

• VDO Oil Pressure sender has 1/8” NPT male threads

• Sender either has 1 terminal (VDO 360-004) or 2 terminals (VDO 360-025)

• If sender has 1 terminal, it is Signal and the Case of the sender must be grounded to RDAC Ground by clamping or brazing a wire

to the case • If sender has 2 terminals, G is Signal and WK is not used

(case is still Ground) • Run a hose off the oil supply with a female 1/8”

NPT fitting and connect to Oil Pressure sender

Wiring:

Connect Signal and Ground as follows:

Signal Oil Pressure Input

Case or Ground terminal RDAC Ground

On Oil Pressure senders with only 1 terminal, a Ground terminal needs

to be brazed onto the case (or clamped) and

connected to RDAC Ground

Connect Oil Pressure sensor to a hose from your oil system with a

female 1/8” NPT thread

Parts Required: 1 x VDO Oil Pressure Sender

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Manifold Pressure

• You can take a manifold pressure line off one of the manifold ports on a cylinder, but this can cause some

pulsing on the line and the sensor is very sensitive and will not display smooth readings. If you do this,

using a restrictor/damper (with a small hole) will help prevent pulsing

• If you can access the intake plenum under the engine that will yield best results

• Use high temp fuel line and fittings to run a pressure line from the intake plenum to the RDAC Manifold

Pressure port. • Once installed, use the setup to calibrate the Manifold

Pressure reading until it reads ambient pressure (not to be confused with altimeter setting).

Manifold Pressure line connected with fitt ing

to intake plenum below engine

Use automotive high temp fuel line (may

need to be ground down to fit into hole

and over nipple)

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Fuel Flow Sender Installation

• Whether you use the Floscan or the FT-60 Red Cube, the wiring is the same.

• A pullup resistor of 5,600 ohms is required between signal and 5V (or 12V). Without

this resistor the fuel flow will not work • Thread size on input and output side is ¼” NPT

Female on both Floscan and Red Cube • Install sender as per instructions supplied with

sender • K-factor on Red Cubes is always 18,000

• K-factor on Floscans is the calibrated number on the Tag x 10 / 3.785. This is

normally around 9,100

Wiring:

Red Wire 12V Power

Black Wire RDAC Ground

White Wire Fuel Flow input (with 5,600 ohm resistor to Power)

Manifold Pressure line connected with fitt ing to intake plenum below

engine

Fuel Flow Sensor location in this Installation

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Tach Setup

• Remove the vent plug on either magneto. Use the vent plug that is closest to the drive side (see picture below). The other vent plug will not produce

results. • Install the T1A9-x into the magneto using thread locker, Loctite 242

or equivalent. Hand tighten plus 1/6th of a turn. Be careful not to

over tighten and strip the magneto housing.

• The unit provides 1 pulse per revolution on 4-cylinder, 2 pole

magnetos, which are the most common. The unit provides 3 pulses per 2 revolutions (1.5 pulses per revolution) on 6-cylinder, 2 pole magnetos, which are the most common.

• It may be necessary to remove the RDAC jumper labelled “BALLAST” to get a good

reading.

Wiring:

Red (or Orange/White)

12V Power

Black (or Blue/White) AND Shield

RDAC Ground

White Wire Rev Input on RDAC

Parts Required: 1 x UMA T1A9-1 (for Slick) or T1A9-2 (for Bendix)

tach sensor

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Fuel Pressure

• Follow mounting instructions with sensor

• Pressure fitt ing on the sensor is 1/8” NPT Female (needs male NPT fitting on fuel pressure hose).

• Outer thread is for optional mounting use and is 5/8-18

Use MGL Avionics Modification “(M)” UMA Fuel Pressure Sensors Only (or any resistive pressure sender):

Typically used for Injected Engines:

100 PSI Fuel Pressure Sender - UMA N1EU100G(M)

Typically used for Carbureted Engines: 35 PSI Fuel Pressure Sender - UMA N1EU35G(M)

There are 3 possible locations for connecting the signal line of the Fuel Pressure Sensor to the

RDAC. Use whichever is available, preferably CHT1/WT/AUX3:

• CHT1/WT/AUX3 • CHT2/CARB ICE/AUX4 • Fuel Level 2

Your setup should reflect the correct Probe Type (linear, voltage, 0.5-4.5V), Correct Location, and Correct Pressure range:

Wiring:

Red (or Orange/White) 12V Power

Black (or Blue/White) AND SHIELD

RDAC Ground

White Wire One of the 3 possible inputs:

• CHT1/WT/AUX3 • CHT2/CARB ICE/AUX4 • Fuel Level 2